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-rw-r--r--arch/tile/mm/highmem.c277
1 files changed, 0 insertions, 277 deletions
diff --git a/arch/tile/mm/highmem.c b/arch/tile/mm/highmem.c
deleted file mode 100644
index eca28551b22d..000000000000
--- a/arch/tile/mm/highmem.c
+++ /dev/null
@@ -1,277 +0,0 @@
-/*
- * Copyright 2010 Tilera Corporation. All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation, version 2.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
- * NON INFRINGEMENT. See the GNU General Public License for
- * more details.
- */
-
-#include <linux/highmem.h>
-#include <linux/module.h>
-#include <linux/pagemap.h>
-#include <asm/homecache.h>
-
-#define kmap_get_pte(vaddr) \
- pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
- (vaddr)), (vaddr))
-
-
-void *kmap(struct page *page)
-{
- void *kva;
- unsigned long flags;
- pte_t *ptep;
-
- might_sleep();
- if (!PageHighMem(page))
- return page_address(page);
- kva = kmap_high(page);
-
- /*
- * Rewrite the PTE under the lock. This ensures that the page
- * is not currently migrating.
- */
- ptep = kmap_get_pte((unsigned long)kva);
- flags = homecache_kpte_lock();
- set_pte_at(&init_mm, kva, ptep, mk_pte(page, page_to_kpgprot(page)));
- homecache_kpte_unlock(flags);
-
- return kva;
-}
-EXPORT_SYMBOL(kmap);
-
-void kunmap(struct page *page)
-{
- if (in_interrupt())
- BUG();
- if (!PageHighMem(page))
- return;
- kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
-/*
- * Describe a single atomic mapping of a page on a given cpu at a
- * given address, and allow it to be linked into a list.
- */
-struct atomic_mapped_page {
- struct list_head list;
- struct page *page;
- int cpu;
- unsigned long va;
-};
-
-static spinlock_t amp_lock = __SPIN_LOCK_UNLOCKED(&amp_lock);
-static struct list_head amp_list = LIST_HEAD_INIT(amp_list);
-
-/*
- * Combining this structure with a per-cpu declaration lets us give
- * each cpu an atomic_mapped_page structure per type.
- */
-struct kmap_amps {
- struct atomic_mapped_page per_type[KM_TYPE_NR];
-};
-static DEFINE_PER_CPU(struct kmap_amps, amps);
-
-/*
- * Add a page and va, on this cpu, to the list of kmap_atomic pages,
- * and write the new pte to memory. Writing the new PTE under the
- * lock guarantees that it is either on the list before migration starts
- * (if we won the race), or set_pte() sets the migrating bit in the PTE
- * (if we lost the race). And doing it under the lock guarantees
- * that when kmap_atomic_fix_one_pte() comes along, it finds a valid
- * PTE in memory, iff the mapping is still on the amp_list.
- *
- * Finally, doing it under the lock lets us safely examine the page
- * to see if it is immutable or not, for the generic kmap_atomic() case.
- * If we examine it earlier we are exposed to a race where it looks
- * writable earlier, but becomes immutable before we write the PTE.
- */
-static void kmap_atomic_register(struct page *page, int type,
- unsigned long va, pte_t *ptep, pte_t pteval)
-{
- unsigned long flags;
- struct atomic_mapped_page *amp;
-
- flags = homecache_kpte_lock();
- spin_lock(&amp_lock);
-
- /* With interrupts disabled, now fill in the per-cpu info. */
- amp = this_cpu_ptr(&amps.per_type[type]);
- amp->page = page;
- amp->cpu = smp_processor_id();
- amp->va = va;
-
- /* For generic kmap_atomic(), choose the PTE writability now. */
- if (!pte_read(pteval))
- pteval = mk_pte(page, page_to_kpgprot(page));
-
- list_add(&amp->list, &amp_list);
- set_pte(ptep, pteval);
-
- spin_unlock(&amp_lock);
- homecache_kpte_unlock(flags);
-}
-
-/*
- * Remove a page and va, on this cpu, from the list of kmap_atomic pages.
- * Linear-time search, but we count on the lists being short.
- * We don't need to adjust the PTE under the lock (as opposed to the
- * kmap_atomic_register() case), since we're just unconditionally
- * zeroing the PTE after it's off the list.
- */
-static void kmap_atomic_unregister(struct page *page, unsigned long va)
-{
- unsigned long flags;
- struct atomic_mapped_page *amp;
- int cpu = smp_processor_id();
- spin_lock_irqsave(&amp_lock, flags);
- list_for_each_entry(amp, &amp_list, list) {
- if (amp->page == page && amp->cpu == cpu && amp->va == va)
- break;
- }
- BUG_ON(&amp->list == &amp_list);
- list_del(&amp->list);
- spin_unlock_irqrestore(&amp_lock, flags);
-}
-
-/* Helper routine for kmap_atomic_fix_kpte(), below. */
-static void kmap_atomic_fix_one_kpte(struct atomic_mapped_page *amp,
- int finished)
-{
- pte_t *ptep = kmap_get_pte(amp->va);
- if (!finished) {
- set_pte(ptep, pte_mkmigrate(*ptep));
- flush_remote(0, 0, NULL, amp->va, PAGE_SIZE, PAGE_SIZE,
- cpumask_of(amp->cpu), NULL, 0);
- } else {
- /*
- * Rewrite a default kernel PTE for this page.
- * We rely on the fact that set_pte() writes the
- * present+migrating bits last.
- */
- pte_t pte = mk_pte(amp->page, page_to_kpgprot(amp->page));
- set_pte(ptep, pte);
- }
-}
-
-/*
- * This routine is a helper function for homecache_fix_kpte(); see
- * its comments for more information on the "finished" argument here.
- *
- * Note that we hold the lock while doing the remote flushes, which
- * will stall any unrelated cpus trying to do kmap_atomic operations.
- * We could just update the PTEs under the lock, and save away copies
- * of the structs (or just the va+cpu), then flush them after we
- * release the lock, but it seems easier just to do it all under the lock.
- */
-void kmap_atomic_fix_kpte(struct page *page, int finished)
-{
- struct atomic_mapped_page *amp;
- unsigned long flags;
- spin_lock_irqsave(&amp_lock, flags);
- list_for_each_entry(amp, &amp_list, list) {
- if (amp->page == page)
- kmap_atomic_fix_one_kpte(amp, finished);
- }
- spin_unlock_irqrestore(&amp_lock, flags);
-}
-
-/*
- * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap
- * because the kmap code must perform a global TLB invalidation when
- * the kmap pool wraps.
- *
- * Note that they may be slower than on x86 (etc.) because unlike on
- * those platforms, we do have to take a global lock to map and unmap
- * pages on Tile (see above).
- *
- * When holding an atomic kmap is is not legal to sleep, so atomic
- * kmaps are appropriate for short, tight code paths only.
- */
-void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
- pte_t *pte;
-
- preempt_disable();
- pagefault_disable();
-
- /* Avoid icache flushes by disallowing atomic executable mappings. */
- BUG_ON(pte_exec(prot));
-
- if (!PageHighMem(page))
- return page_address(page);
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- pte = kmap_get_pte(vaddr);
- BUG_ON(!pte_none(*pte));
-
- /* Register that this page is mapped atomically on this cpu. */
- kmap_atomic_register(page, type, vaddr, pte, mk_pte(page, prot));
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_prot);
-
-void *kmap_atomic(struct page *page)
-{
- /* PAGE_NONE is a magic value that tells us to check immutability. */
- return kmap_atomic_prot(page, PAGE_NONE);
-}
-EXPORT_SYMBOL(kmap_atomic);
-
-void __kunmap_atomic(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
- vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
- pte_t *pte = kmap_get_pte(vaddr);
- pte_t pteval = *pte;
- int idx, type;
-
- type = kmap_atomic_idx();
- idx = type + KM_TYPE_NR*smp_processor_id();
-
- /*
- * Force other mappings to Oops if they try to access this pte
- * without first remapping it. Keeping stale mappings around
- * is a bad idea.
- */
- BUG_ON(!pte_present(pteval) && !pte_migrating(pteval));
- kmap_atomic_unregister(pte_page(pteval), vaddr);
- kpte_clear_flush(pte, vaddr);
- kmap_atomic_idx_pop();
- } else {
- /* Must be a lowmem page */
- BUG_ON(vaddr < PAGE_OFFSET);
- BUG_ON(vaddr >= (unsigned long)high_memory);
- }
-
- pagefault_enable();
- preempt_enable();
-}
-EXPORT_SYMBOL(__kunmap_atomic);
-
-/*
- * This API is supposed to allow us to map memory without a "struct page".
- * Currently we don't support this, though this may change in the future.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- return kmap_atomic(pfn_to_page(pfn));
-}
-void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
-{
- return kmap_atomic_prot(pfn_to_page(pfn), prot);
-}